Swift 3 - 未调用完成处理程序

Question

EDIT: I'm using Swift 3.0 and Alamofire 4.0

In my system I have a list of materials, each material contain a list of bundles. Im trying to request these bundles via webservice and then populate the next view (in this example I'm trying to only print the data fetched), but my Completion Handler is not being called (ps: i'm beginner and that's the first time i'm leading with async prog). Any idea why?

The function that fetch data from WS is:

  func fetchBundles(materialCode: String, completion: @escaping ([ProductsBundle]?) -> Void ) {
    var bundlesAdded = [ProductsBundle]()
    let url = baseApiURL + "material-cavaletes/" + materialCode
    print(url)

    Alamofire.request(url, headers: headers).responseJSON {
      response in
      if let result = response.result.value {
        var results = JSON(result)["results"]

        for res in results {
          bundlesAdded.append(self.getBundleFromJson(json: res))
        }

        completion(bundlesAdded)
      }
    }
  }

And the function call ,that should get the data and update the view, is:

WebApi.sharedInstance.fetchBundles(materialCode: materialBeingListed.id, completion: {
  (bundlesAdded: [ProductsBundle]?) in
  guard let myBundles = bundlesAdded else {
    print("erro")
    return
  }

  print (myBundles)
})

I put some breakpoint at the code and noticed that the line "print (myBundles)" is never being called. I have no clue why... :(

Answer 1

I think you might be handling your Alamofire request incorrectly. Try this:

Alamofire.request(url, headers: headers).responseJSON {
  response in
    switch response.result {
      case .success(let data):
        let json = JSON(data)
        print("JSON: \(json)")
        break
      case .failure(let error):
        print("Fetch failed :( error: \(error.localizedDescription)")
        switch(error._code) {
          case NSURLErrorTimedOut:
            print("Timed Out")
          default:
            print(error._code)
        }
    }
}

Once you see what the JSON data looks like you should be able to access it correctly. Typically JSON becomes a Dictionary when you unserialize it.